Pbogeam-seiectik g ciecuits



` l 27. May 17. 9 J, F.1ooMEY PROGRAM SELECTING CIRCUITS Fil'ed Dc. rl0,1923 /NVENTDR ef. l? 770mg/ A TTORNE V.

Patented May i7, i927.

ldizt unire stares earner JOHN F. TOOMEY, 0F NIE-"iii" YORK, N. Y.,ASSGNGR TO AMERCAN TLEPHNE AND TELEGRAPH CGMPANY, A CQRPORATON 0F NEWYORK.

PROGRAM-SELECTNG CIRCUITS.

Application filed December 10,V 1923. Serial No. 679,753.

lhis invention relates to transmission sys tems for sending); programsover wires, and more particularly to :rraugements tor the selection otprograms tor such systems.

Vhere wire lines, such as ordinary telephone lines, tor example. areused ier the transmission ot entertainment programs, such as news,lectures, concerts and the like, is desirable that some arrangement belnovided whereby the subscriber may automatically select the particular'program which he desires to hear. ln accordance with the presentinvention, it is proposed to accomplish this result by providingl aselective switch at the central other; which may be directivelycontrolled by an operator to connect the terminals of the subscribefsline to the terminals of any one ot a number ot trunks each leading to adifferent program. `When the subscriber desires a particular program, hecan then call up over his telephone .line in the usual manner and informthe operator of the program which he desires, and the operator can thenconnect that program to the line.

By the use of a directively controlled seleotive switch for selecting aprogram, it becomes immaterial whether the program be transmitted atvoice frequencies or carrier frequencies, and it also becomes immaterialwhether the several programs be transmitted at the same `frequency orwhether different carrier frequencies are used for diilerent programs.By permitting the directive switch to be controlled by the operatorrat-her than the subscriber, circuit complications due to dialing overthe subscribers line are eliminated.

The invention will now be more fully understood from the followingdescription when read in connection with the accompanying drawing, thefigure ot which illustrates a circut arrangement whereby a directiveswitch may be used to select programs.

Referringto the drawing, L designates an ordinary telephone transmissionline terminating in the usual subscribers set S at one end andterminating at the central oiiice in the multiple jacks J and J.Normally the telephone line L is connected over the contacts of acut-ott' relay CO to a transformer 20, whereby the line is associatedwith conductors l1 leading` to a directive switch Dit tor connecting theline with the desired program. rihe line relay LR has its windingsconnected on either side of the condenser 2l intermediate between the.two 'halves oi the secondary winding oit the transformer 20. The cutoffrelay CO is so arranged that when it is operated the line L isdisconnected from the transformer 2O and hence from the line relay LR,and is connected directly to the tipand ring` terminals of themultiplejacks J and J.

ln order that the line may be used for program transmission during suchtime as it is not being' used for ordinary telephone purposes, a programreceiver such as the loud speaker LS is provided at the subscribersstation, said receiving device beine; bridged across the line throughthe back Contact of the switcbhook l() and through the contactof a relay23. The relay 23 is so arranged that it will be operated to connect theloud speaker to the line upon the momentary actuation of the uppercontact of the non-locle` ing key K. On the other hand,r the relay 23 isso arranged that it will be released to dis connect the loud speakerupon takingthe receiver from the switchhook to mak-c a call or upon theoperator insertingl a plug into one of the multiple jacks to call thesubscriber. It may also be released by the subscriber when he no longerdesires to hear a program by momentarily opening the lower contact ofthe lrey K.

At the central otiice the wipers 25 and 26 of the directive .switch` DBare arranged to connect the conductors 1l to any one of a plurality oftrunlrsA, B, C, D, E, etc.. leading' to different voice frequencyprograms.

In order to operate the switch DR a stepand 28, as will be describedhereinafter. The

so arranged that it will be oper switch is l by step under the controler 'the ated step dial and will be released and restored to normal bythe mon'ientary operation ot the release magnet.

Further details et the apparatus will he Clear from the desoription otthe operation which is as tollon's: lVhen the line L is not in use fortelephonie purposes and the subscriber desires to hear a program, such,for example, as the program C, the subseriber will remove. his receivertrom the switch-- hook 10, thereby operating' the line relay LR to eal'lthe attention ot the operator at the central otiiee. The operator,inserts a plrnev in the answering` jaeli in the usual manner, therebyoperating the ente-.l relay C() and connecting the line L to the jack J.ll pon ascertaining the program desired by the sub-- seriber, theoperator n'ill Withdraw the plug; et her Cord Circuit from the answerfarle. J, thereby releasing` the ent-olf relay C() and again connectingthe line L to the non duetors ll through the transtormer Q0. Theoperator then inserts the ,A P in the jack J and operates the dial L, inthe same manner as is Customary in the oiieration ot machine switchingdials. l? or efiainple, the dial may have each ot holes provided with aletter corresponding to each o't the programs. The operator, in the caseassumed, Will insert her finger .in the hole marked C and rotate thedial until her finger comes against the stop, when the dial is released.As soon as the dial begins to re tate, the ott-normal Contact 29 ot thedial is Closed and remains elosed until the dial is restored to normalatter being released. The closing,Y of the oil-norma-l Contact oompletesa circuit trom ground, over the eontaets 29 and 32, through the Contactsof the plugr P and jael; J and through the Winding ot slow release relay27 to battery. Relay 27 is at onre energized an d is sulteiemtly slow inreleasingr its armature so that its armature Will not be releasedthrough momentary interruptions of the eireuit et the dial let, due tothe dialing` operation.

Relay 27 at is itront Contact Completes a circuit over the right-handhaelt; contant ot relay 2S 'tor the release magnet RM. Relay 27 at thesame time elosesa circuit Vfor the slow operating relay so that a'tter amoment the reli i 28 opens the Circuit ot the re lease. ma gnat RM'. Themomentary euer-gim-r tion ot the release magnet RM. lunvever. causes thedirective siviteh DR to be released and restored to normal. betere anyimpluf-ies are beine,` transmitted 'trein the dial 24, the operationsWhieh have just been described taking plaee while the dial is beingadvaneed. As is Well known, the impulses sent trom the dial artransmitted after it is released. Relay 28,. upon being energized,Closes a eirenit trom battery, over its lett-hand it'ront contant,through the winding oit the stepping' magnet SM, over the eontaets olthe jaeli 2.; and have been advanced to the r-'rutaets ronneeting theeonduetrns ll to the dernreifl pug'ograrn, which in the ease assumed, ithe program (l. Upon the dial being re store to normal, the eti-normalleonlaet E35) is opened and Consequently. the slow acting; relay QT isreleased. This rel'aj,v in t; 1 opens the circuit of the relay n iii).vhieh Closes a circuit of the release magnet RM at one point, hut theeireuit opt said magnet has been preifiously opened by the Contact ofthe relay 2T, so that the release magnet is not energia-:re at thistime.

In the meantime, the subscriber hangs up his receiver' and momentarilyoperates the non-looking key K to close its Contact 33. This completes aeireuit from battery through the right-hand Winding of the line relayLR, over the lower back Contact et the eut-ott relay CO, over thevring-3r conductor ot the line L, over the baol Contact of the sWitehhookl0, over the normally Closed contaet 3l of the key K, over themomentarily closed.y Contact of said key, through the winding;` ot therelay 23, over the tip oonduetor oft' the line L, over the upper backContact of the eut-ott relay C() and through the lett-hand winding otthe line relay LR to ground. Owing to the high resistance ot the relay23, the line relay LR is not aetu ated by the Circuit above traced, butthe relay 23 is operated and. at its inner front eon- W' taet completesa looking circuit independent of the eontaet $553 of' the key K. At itsouter tronteontaet relay 2? bridges the loud speaker LS aeross the lineso that the sul seriber may non' listen to the program transmitted overthe eondrmtors l14 and thun I, the transformer 20 to the line.

It a Call should come in ,for the subseri ber while the eirouit isbeing;- used 'tor reception et a program, the operator inserts a plugot' her cord eireuit in one of the multiple jaelis, tor example, thejack; J", thereby energizing the eut-ott relay CO. The eut-olli relayshifts the connections ot the line L from the conduetors l1 to themultiple jacks, to which the oord eireuit is Connected. This momen--tarily interrupts the circuit previously traced for the relay 3, whichreleases and opens its looking` Circuit before a new eireui't isestablished for said relay to the battery associated with the cordcircuit. Accordingly, the relay `23 disconnects the loud scriber hangsup his receiver and when the `he merely removes the receiver from theswitchhook l0. lhis opens the locking circuit of' thc relay 23 andcauses said relay to be released and disconnect the loud speaker LSfromthe line in themanner already described. At its upper contact theswitchhook l completes a low resistance circuit through the line relayLR, as already described. Upon observing the glowing ot the line lamp,the operator inserts a plug' in the jack J, thereby operating thecut-ofi relay CO to disconnect the line L from the conductors 1l andconnect it to the `multiple jacks. The telephone connection is thencompleted in the usual manner and the conversation proceeds. At the endof the conversation the subscriber hangs up his receiver and upon theconnection being taken down, the subscriber can again listen to theprogram by actuating the `key K to close the contact 33, as alreadydescribed.

When the subscriber desires to discontinue the program connection heoperates the key K to niomentarily open the contact 31. This releasesand unlocks the relay 23, thereby disconnecting the loud speaker LS fromthe subscribers line. The setting of the switch DR is not disturbed bythis operation. It the subscriber should thereafter desire to change theprogram, he does so by calling up the operator, as already described,whereupon the operator will plug the dial 24 into the jack J and dial anew program. A s already described, the initial operation ot the dialcauses the release magnet RM to restore the switch DR to normal so thatin response to the pulses transmitted, it will `lhat is kclaimed is:

hln a wired program system, a Subscribers telephone line terminating ina subscriberis telephone apparatus at the `subscribers station,switching means at the central office whereby a connection may beestablished between said subscribers line and f for establishing aconnection between saidy line and any desired trunk, and controllingmeans at the central oiiice whereby the operator may control theoperation of said selective switching means. i

in a wired programsystem, a subscril'iefs telephone .line tern'iiuatingin a subscribers telephone apparatus at the subscribers station,switching means at the central oilice whereby a connection may ,beestablished between said subscribers line and another subscribers line,a pluralityV of trunksat the central oiiice upon which programs may beimpressed, a directive switch independent of said iirst mentionedswitching means at the centraloiiice .for establishing a connectionbetween said line and any desired trunk, and controlling means at thecentral oiiice whereby the operator may control the operation of saiddirective Switch to select a program. l

ln a wired program system, a subscribers telephone line terminating in asubscribers telephone apparatus at the subscribers station, switchingmeans at the central oiice whereby a connection may be establishedbetween said subscribers line and another subscrihes line, a pluralityof trunks at the central ofice upon which programs may be impressed, adirective switch independent ofA said first mentioned switching' meansat the central office for establishing a connection between said lineand any desired trunk, controlling means at the central oiiice wherebythe operator may control the operation ci said directive switch toselect a program, and means for restoring said switch to normal at thebeginning of its operation to select a program.

li. In a wired program system, a subseriberls telephone line terminatingin a subscriberis telephone apparatus at the subscribers station,switching means at the central ofce whereby a connection may beestablished between said subscribers line and another subscribei"s line,a plurality of, trunks at the vcentral otiice upon which programs may beimpressed, a step-by-step switch independent of said rstmentionedswitching means at the central otice for switching said subscribers lineto a desired trunk, and means at the central oiiice whereby the operatormay control said switch.

ilo

lill) l besaen 5. In a wired program system, a subscitiberrs telephoneline terminating in a subscriber-7s telephone apparatus atthesubscxibeins station, switching ymeans at the central ofiicelwlmreby aconnection may be' cst-ablished between said subscribers line andanother subscribcns line, a plurality of trunks. at the cent rel..oiiice upon which prof `seribers telephone apparatus atV thesubscniberisfetation, switching means :it the central office whereby aconnection may be established bet-Ween said'subscribers line and anothersubscriber-7s line, a plurality of Vtrunksaty the central otlice uponwhich programs maylbe impressed7 an impulse-oper ated. selecting switchindependent of said first mentioned switching means at the centraloffice vand an impulse sender. at thel central oilice fortransmittingimpulses to said switch to operate the same to establish aconnection between said subscribers line and any desi red trunk.

7. In a. wired program system, a subscribe1"s telephone line terminatingin a subscribcis telephone apparatus atthe sub scribers station,switching means-nt the central officewhereby a connection may be'established between said subscribers line and. another .snbscribensline, a plurality oi trunks at the central oltice uponA which programsmay be impressed, an impulse-operated selecting switch independentofsaid first mentioned switching means at the central otiice, an impulsesender at the central ofiice for transmitting impulses to seid switch tooperate the same to establish e connection between said subscribers lineand any desired trunk, and means' to yrestore said switch -to normal atthe beginning of its operation to establish x11-connection to anothertrunk.

In testinony whereof, I `have signed rmy name to this specification this'7th vdey of December, 1923.

JOHN F. TOOMEY.

